The former spy agency boss who approved the illegal surveillance of Kim Dotcom has been appointed to conduct a review into the Rena disaster - a choice that baffles the MP who has pushed for such a inquiry.

The inquiry, revealed by the Herald this week, was confirmed by Maritime New Zealand yesterday, and former Secretary of Foreign Affairs and Trade Simon Murdoch was named as the man to lead it.

Mr Murdoch was acting director of the secretive Government Communications Security Bureau when it began spying illegally on internet tycoon Dotcom, triggering a scandal engulfing Prime Minister John Key.

Green MP Gareth Hughes began calling for an independent high-level inquiry into the Government's response to the grounding of the Rena in the weeks after the Bay of Plenty environmental disaster that started a year ago today.

Yesterday, he said the new review would not be broad and independent enough, and he questioned Mr Murdoch's appointment.

"Given there are three current investigations of this unlawful spying by the GCSB, it baffles me why this Government would pick such a controversial appointee - surely there are other high-calibre candidates."

The review would focus on Maritime New Zealand's response to the grounding and factors which contributed or limited its effectiveness.

It would not involve public submissions, but those agencies that took part in the response, and would be overseen by the bosses of the Ministry of Transport and Maritime New Zealand.

Mr Hughes felt the scope of the review was too narrow, and that the public should get a say.

Labour's environment spokesman, Grant Robertson, also believed the review fell short of what was needed.

"This is not an inquiry as had been promised," he said. "It is essentially an internal review of Maritime New Zealand's processes.

"The people of the Bay of Plenty and New Zealanders in general deserve better than this response to our worst maritime environmental disaster."

Maritime New Zealand director Keith Manch said an independent review for such large scale incidents was standard practice for emergency response organisations.

"There will be things that have been done very well, but inevitably there will be areas where things could have been done better and we can take lessons from this incident."

The causes of the grounding had been established during the criminal investigation that led to the prosecution of the master Mauro Balomaga and second officer Leonil Relon.

Balomaga told the Herald last week he hoped some good could come out of the disaster, including improvements among authorities.